What type of roosts?

[lablover]

I have a dog kennel coop, and the easiest roost to put up were branches/small limbs. I just moved my chickens in to this coop, and they seemed to have a hard time adjusting to the new roost. They are used to roosting on a 2x4 ripped in half. So, should I just stick out with the branches? They're pine, but they're good and round. Or should I try to get a full 2x4 so that they half a good flat base?